The present invention relates to curable compositions and composite coatings on substrates containing tricarbamoyl triazines and process for applying the composition for mar and abrasion resistance.
Of increasing concern in many geographic areas is the encounter with acidic precipitation. Coatings, particularly automotive original equipment coatings, that are resistant to such environmental conditions like those that are resistant to etching by atmospheric acid precipitation ("acid etch resistance") are becoming increasingly desirable. Original equipment manufacturers are requiring that coating systems demonstrate acid etch resistance.
In addition to the requirement of acid etch resistance, original equipment coatings must also demonstrate mar and abrasion resistance; i.e., the appearance of the coating must not be detrimentally affected when the coating is contacted with an abrasive material. Mar and abrasion resistance is a desirable property particularly due to the popularity of commercial car washes where brushes are often used to wash car bodies.
A number of commercial coating systems which demonstrate acid etch resistance do not provide adequate mar and abrasion resistance. Microparticulate materials such as silica, metal sulfides, and crosslinked styrene-butadiene have been added to these coating systems to improve mar resistance, but gloss and distinctness of image of the systems are adversely affected due to light scattering at the particle surfaces.
Recently, curing agents for coatings with active hydrogen-containing materials have been developed that are triisocyanato or tricarbamoyl triazines as shown in U.S. Pat. Nos. 4,930,213 and 5,084,541. The U.S. Pat. No. 4,930,213 ('213) patent shows the use of these curing agents in a coating composition to improve environmental resistance for powder coatings, coil coatings and can coatings. As noted on page 1 of the '213 patent, when the active hydrogen-containing compounds are hydroxylated polymers, environmentally resistant coatings are provided.
It would be desirable to provide a curable composition for use as a coating which avoids the marring problems of the prior art coating systems while maintaining excellent acid etch resistance and appearance properties.